Process of treating ferrotungsten.



UNITED STATES PATENT OFFICE.

.HHILIP M. MOKENNA, OF WASHINGTON, DISTRICT OF COLUMBIA.

' PROCESS OF TREATING FERROTUNGSTEI No Drawing.

substances, particularly sulfur, phosphorus and carbon, in objectionablequantities, espccially whenthe product is to be used in then'ianufacture of what is known as high speed steel. 7

The present invention has for its object the elimination, or the,n'iaterial reduction in percentage, of such deleterious substances, andespecially the elimination of the sulfur content I In accordance withthe present invention the lump ferro tungsten alloy is reduced to rusand carbon materially reduced, while, the

a connninuted condition, preferably by grinding. Thiscomminuted ferrotungsten is then subjected to tl e flCtlOIl,0'f an acid which acts uponthe*materia-l to combine with some or all of the impurities, with theresult that the sulfur may bepractically eliminated and the percentageof phosphometallic condition of the form-tungsten alloy (iron tungstide)is snot changed. After treatment with the acid the comminuted sub--'stance is washed with water to eliminaterthe acid and any materialsdissolved therein, and subsequently dried for use, The acid which ispreferably used is muriatic acid of commercial gravity that is to say,approximately of 20 Baumc, and the proportion of acid used is preferablyabout thirty-seven and one half per cent. by wei ht of the ferrotungsten treated,- but acids aving similar properties may be employed?as will be obvious to chemists familiar with metallurgical cl'ieinistry.For example, another acid which might be employed, although, at thistime somewhat more, expensive, is hydrofluoric acid; orsulfurioacidpmight be used, the use of the latter, however, requiringthat the sulfates shall be completely washed out, and as :1 commercialproposition this may be somewhat more difiicult and expensive than thewashing necessary where muriatic acid is Specification of LettersPatent.

sten. 3. The process of removing sulfur from Patented n 1:2, 1911;.

Application filed August 11, 1916. Serial No. 114. i79.

in the practical utilization of the invention, it is found. that, whilethe sulfur is removed and the percentage of phophorus and carbonmaterially reduced, there is also some remoyal. of manganese .and iron;although the greater portion of the. iron remains com: bincd with thetungsteii and is not acted upon. Thus, the percentage of tungsten isincreased and while the chemical reactions are not deemed to be.important for a complete Iinderstandii1g of the invention; nor is itbelieved that the action is fully understood at this time, still it maybe stated that it is applicants belief'that the sulfur is completelyvolatilized as hydrogen sulfid, and that the phosphorus and carbon, or alarge proportion of the phosphorus and carbon are removed by theformation of hydrogen carbids and phosphids. Regardless ofthe chemicalre-action in connection with any one of these substances, the processset forth results in the elimination of'the sulfur and a materialreduction in the phosphorusand carbon content-s, without changing the metallic condition of the iron tungstid' alloy,-

a result which is of great commercial value in the production of formtungsten.

After the reaction has taken place the solution is completely washed outof the remaining: ferro-tungsten with water, and the conuninutedform-tungsten itself is dried, when it is ready for subsequent use.either in the manufacture of high speed steel or other wise.

\Vhat is claimed is 1. The process of treating sineltecl ferrotungstenalloy for the removal of metalloid impurities, which consistsincomminuting the sinelted mass, then subjecting the comninu'tedmaterial to the action of an acid which will combine with the impuritiesin the production of hydrogen compounds and which will not combine withthe metallic alloy.

i 2. The process of treating smelted ferret tungsten alloy for theremoval of metalloid impurities, which consists in comminutin'g' whichwill combine with the impurities in the production of hydrogen compoundsand which will not ,combine with the metallic alloy, then Washing outthe acid solvent and finally drying the comminuted form-tung- 5 notcombinqaigith the 11 1eta11ic tungsten alloy,

*and drying the comn inIitGdQQZjO QQQI;

4. The process of removing sulfur, phosphorus and carbon from'smeltedferro-tungsten, which consists in grinding the smelted mass, thentreating it with muriutic acid of approximately 20 Baum and finallywashing and dryli "11 commmuted product.

PHILIP M. MGKENNA.

